Wet winter, spring kind to Delta smelt

Friday

Dec 23, 2011 at 12:01 AM

The Delta smelt - that finger-long fish whose welfare was the subject of intense political debate during the recent drought - has rebounded to levels not seen in a decade, the California Department of Fish and Game reported Thursday.

Alex Breitler

The Delta smelt - that finger-long fish whose welfare was the subject of intense political debate during the recent drought - has rebounded to levels not seen in a decade, the California Department of Fish and Game reported Thursday.

But even after this year's 10-fold increase in population, the smelt remains but a fraction of its former abundance.

And that says something about the fish's perilous state in recent years.

"Hopefully, this is the start of a new trend," said Carl Wilcox, Bay-Delta regional manager for Fish and Game.

The most recent upswing can be attributed mostly to the fact that so much water flowed through the Delta following a wet winter and spring, Wilcox said. Fresh water flowing downstream can dilute pollution, create better feeding conditions and help the 3-inch smelt hide from predators and escape the influence of giant pumps near Tracy.

Cities and farms that take water from the Delta also got record-high deliveries this year, creating a rare confluence of events in which both fish and farmer prospered.

That wasn't the case during the three-year drought, when some farmers south of the Delta got less water as the federal government attempted to protect smelt and other species. The cutbacks triggered intense arguments about endangered species laws and reinvigorated discussion of building a peripheral canal or tunnel to bypass the Delta entirely.

"A 10-fold increase (in smelt) was definitely beyond my wildest hopes for the species," said Jon Rosenfield, a biologist with the environmental group The Bay Institute. "I think this number buys us a little bit of time to enforce the protections and do the other things, like habitat restoration and water-quality cleanup, which we need to do."

Smelt weren't the only species to benefit from lots of water rolling through the Delta. Striped bass - a favorite among local fishermen - rose to an abundance not seen since 2006 after declining to a record low in 2010.

Longfin smelt - a cousin of the more notorious Delta smelt - and two species of shad also became more prevalent.

Perspective, however, is sobering.

The number of smelt this year is still only about 20 percent of the number seen in 1970, the best year on record.

The number of stripers is less than 1 percent of the number seen in 1967, the best year on record for that fish.

"We've seen a pretty good bounce," Rosenfield said. "I'm still not willing to state there's been a recovery."